Septic tank

[txdon]

I had my septic system pumped out today after 5 years - no problems.

The system is 750 gallons, two round cement tanks connected by a 4" PVC then draining to a field line in a field of deep sugar sand.
He did notice more sludge in the second (250 gallon) tank.

The pump guy also noticed that I did not have a sanitary T on the 4" pipe coming into 500 gallon septic tank. It was just a straight 4" PVC pipe.

The out going pipe did have an elbow and an extension piece that went down 16" into this 500 gallon tank.

The out going pipe out of the 500 gallon tank goes into a 250 gallon tank and again it was just a straight 4".

The out going pipe out of the 250 gallon tank did have an elbow that had a 4" PVC going down 9" into the tank.

Do I need to add sanitary Ts to the two 4" PVC pipes coming into each tank?

If so, how far should I extend the pipe going down on the Ts?

Or should I leave everything alone because it's working?

(Now is the time to make any adjustment while the level is low.)

 

[JBourquin]

The new tank I just bought had a "T" on the inlet side. I'm still not 100% sold on it. If anything going into the tank floats, wouldn't that cause a blockage there? I guess it depends on how high your inlet pipe is above the top of the scum line. If there's a possibility of scum backing up into the pipe you should have a "T" on there.

 

[MAN IN BLACK]

The exact purpose of the T's, is to prevent blockage from sewage or solids inside the tank blocking the inlet.
I would put some on...better be safe than sorry...picture yourself trying to free a blockage in the inlet...nasty, dirty , smelly and very unpleasant job.

 

[HeLa]

while you have dry access, i would put a sani-tee on the inlet of both tanks. they help attenuate the flow and increase the settling of solids. additionally, if you don't have an effluent filter on the outlet side of the second tank i would add that as well. this helps keep solids from entering the field. note that you'll probably want to have riser access to this filter for servicing it without digging.

 

[oosik]

Properly designed - a septic tank will have an inlet baffle - a baffle between the first & second compartment and a baffle on the outlet from the tank. These baffles can be cast-in-place or 4" plastic "T's". The exact design of the baffles is dictated by local sanitary codes/laws.

 

[Western]

Properly designed - a septic tank will have an inlet baffle - a baffle between the first & second compartment and a baffle on the outlet from the tank. These baffles can be cast-in-place or 4" plastic "T's". The exact design of the baffles is dictated by local sanitary codes/laws.

Mine has those backflo thingys, but I wish I had had them install an access at the exit point of the last tank for adding root killer that foams..

 

[txdon]

This septic system is grandfathered in and it is what is - acutally working pretty good - the lines have never clogged up. It's on top of a sand hill.

The inlet to the 500 gallon tank is about a 1/2" above the scum line. There are no baffles only the two connecting tanks (500 and 250 gallon).

So, if anything going in floats, will it be will be stuck in the T and cause a backup until it sinks or comes out the top of the T? Could this back things up?

I'm going back and forth on this - to T or not to T the inlets, that is the question.

The decision has to be made soon the level is rising.

 

[PILOON]

Recently a client's system was backing up and I was called to consult.
System was pumped last year as it is every 2 yrs in compliance with bylaws.
This is a chalet that is not heavily used.
I discovered that the solids had accumulated and hardened in that they exited the input and literally stopped by the baffle.
A simple poking with a stick collapsed the foot long 'plug' and everything returned to normal.
I instructed them to flush a lot of water in the future.

At first it simply looked like someone had inserted too much pipe and it was only when I poked with a stick to show them what I meant that the 'plug' dropped away. (dirty pipe and the 'plug' all looked the same color and was perfectly round as well)

All this to say baffles may not always be a good thing and I think unnecessary with dual compartment tanks or dual tanks.
I'd personally leave well enough alone.

 

[Raspy]

One of my septic tanks has a tee on the inlet pipe of the first section. It doesn't make a lot of sense to me and my neighbor recently had a clog there on his system after coming home from vacation. The septic guy told me the tee was to allow gasses to flow back up the pipe and get to the vent. Maybe, but an open pipe would do the same thing. I'm careful to send plenty of water down the pipe before leaving for any period.

The downturned pipe that leads to the second section prevents solids that either float or sink from getting through to the second section.

 

[Raspy]

Ooops, double post

 

[txdon]

Raspy, that is what I was thinking. The inlet T would be the first place a clog would happen. I have also read where the inlet T stops the water coming in from doing unnecessary churning. Then I also read where the inlet should be lower than the outlet T and then I read the reverse. I'm inclined to let what is working continue to work. The septic clean out guy did not see the downturned outlet pipes because I did not have those access holes located. I only opened the access holes above the inlet pipes. He thought I had just a straight outlet pipes like the inlet pipes and he suggested 4 Ts.

After he left I found the other access lids above the outlet pipes. I had to remove the square cement lids with hydraulic jack a pipe and a block of wood - luckily they did not crack when they popped up.

I have learned that the scum layer can be 4" - 8" thick and the outlet downturn pipes are 16" and 9" so I should be OK there. However if a T is placed at the final outlet you would be able to tell if sludge is entering the field line.

I still have a few days before it fills to the outlets and am still researching.

 

[dave1949]

I think the outlet tees you have now should be enough, and as you say it's working. You don't want to 'improve' it until it's broken, or barely works, as often happens.

If it acts up you should eat a low-fiber diet.

 

[txdon]

If it acts up you should eat a low-fiber diet.

Build bigger or add an outhouse would be an option, but restrict diet - not in Texas.

 

[300UGUY]

I had a septic pumper tell me that we must have a good diet - our turds floated!

 

[doxford jim]

I had a septic pumper tell me that we must have a good diet - our turds floated!

Full of hot air - sorry I couldn't resist that one !

 

[300UGUY]

Full of hot air - sorry I couldn't resist that one !

I had that one coming!

 

[C4Ranch]

5 yrs, no problems..... I wouldnt mess with something that's working. JMHO.

 

[PILOON]

My field by necessity is uphill from the tank so I need a sewage pump.
A recent power failure caused the float switch to malfunction (got tangled) and I had to pull the lid. Problem was that the ground was frozen hard making lid removal a problem.
We built a fire over the lid to thaw the earth, untangled the line and all is back to normal.